JP2001106833A - Pneumatic tire containing rubber member containing liquid polysulfide compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire having excellent properties. SOLUTION: Provided is a pneumatic tire containing a rubber member, wherein the member contains 100 pts.wt. (a) at least one elastomer containing olefinic unsaturations and 1-20 phr of (b) a liquid organic polysulfide polymer having a molecular weight of 500-10,000. In a preferable embodiment, the rubber member is selected from the group consisting of an apex, a wire coat, a ply coat, a squeegee compound, a gum strip, a chafer, an inner liner, a reinforcing side wall insert, a tread, and an exposed side wall.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid polysulfide compound useful for a rubber composition used for a pneumatic tire.

[0002]

BACKGROUND OF THE INVENTION Polysulfide rubbers have long been known in the art and have certain excellent properties, such as excellent resistance to a wide range of solvents, good resistance to atmospheric oxidation and weathering, metal adhesion, and It is known to have elasticity retention over a relatively wide temperature range.
These were originally manufactured as solid polymers. Thereafter, a solid polymer splitting process (such as disclosed in U.S. Pat. No. 2,466,963), which upon curing forms a liquid polythiomercaptan polymer which can be a rubbery material having the desired properties described above. It has been developed. Liquid polymers are particularly useful in a wide range of applications because of the ease with which liquid materials can be handled and can be made into the desired form that, when cured, can result in an elastomeric molded article.

[0003] As described in US Patent No. 2,466,963, polysulfide polymer molecules are generally characterized in that R can vary widely within a particular structure, but generally, alkylene or oxy groups interconnected by disulfide groups. It is characterized by a repeating unit (RSS) which represents the same or different divalent organic group which is a hydrocarbon group. Although a variety of such polymers can be produced, there are currently a limited number of commercially important polymers. Some commercially important liquid polymers are available from Industrialland E
nginering Chemistry, No. 42
Vol., P. 2217 (1950) and Vol. 43, p. Three
24 (1951) Fettes and Jorczak
The article is described in detail. As noted in these articles, commercially available liquid polysulfide polymers (e.g., LP-2, LP- LP available from Morton International of Chicago, Ill.)
3, LP-12, LP-31, LP-32 and LP-
33 polymer) ("LP" is a registered trademark of Thiokol) is generally prepared from bis-β-chloroethyl-formal and has essentially the following structure:

[0004]

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Wherein x is an average value of about 2 to about 59, preferably about 5 to about 20. Morton International also has LP-3 and LP-3, respectively.
ELP-, an epoxy-terminated derivative of 3 polysulfide
3 and ELP-33.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a pneumatic tire including a rubber member containing a liquid polysulfide compound.

[0007]

A pneumatic tire containing a rubber member, wherein the rubber member has (a) 100 parts by weight of at least one elastomer containing olefinic unsaturation, and (b) a molecular weight of 500 to 10,000. A pneumatic tire comprising 1 to 20 phr of a liquid organic polysulfide polymer is disclosed.

The present invention relates to a pneumatic tire including a rubber member containing an elastomer containing olefinic unsaturation. "Rubber or elastomer containing olefinic unsaturation" includes natural rubber and various raw and regenerated forms thereof, and various synthetic rubbers. In the description of the present invention, "rubber" and "elastomer" can be used interchangeably unless otherwise specified. "Rubber composition", "compounded rubber" and "rubber compound" can be used interchangeably and refer to rubber blended or mixed with various components and materials, such terms being used in the rubber mixing or rubber compounding technical field. Are well known to those skilled in the art. Representative synthetic polymers include butadiene, and homologs and derivatives thereof, such as the homopolymerized products of methylbutadiene, dimethylbutadiene and pentadiene, and butadiene or homologs or derivatives thereof and other unsaturated monomers. It is a natural copolymer.
Other unsaturated monomers include acetylenes, such as vinyl acetylene; olefins, such as isobutylene (copolymerized with isoprene to form butyl rubber); vinyl compounds, such as acrylic acid, acrylonitrile (polymerized with butadiene to form NBR) Methacrylic acid and styrene (polymerizes with butadiene to form SBR),
And vinyl esters and various unsaturated aldehydes, ketones and ethers, such as acrolein, methyl isopropenyl ketone and vinyl ethyl ether.
Specific examples of the synthetic rubber include neoprene (polychloroprene), polybutadiene (including cis-1,4-polybutadiene), polyisoprene (including cis-1,4-polyisoprene), butyl rubber, styrene / isoprene / butadiene. Rubber, copolymers of 1,3-butadiene or isoprene with monomers such as styrene, acrylonitrile and methyl methacrylate, and ethylene / propylene terpolymers, also known as ethylene / propylene / diene monomers (EPDM);
In particular, an ethylene / propylene / dicyclopentadiene terpolymer. Preferred rubbers or elastomers are natural rubber, polybutadiene and SBR.

In one aspect, the rubber is preferably a rubber based on at least two dienes. For example, cis-1,4-polyisoprene rubber (natural or synthetic, preferably natural), 3,4-polyisoprene rubber, styrene / isoprene / butadiene rubber, emulsion and solution polymerization-derived styrene / butadiene rubber, cis-1,4 4-
Preferred are combinations of two or more rubbers, such as polybutadiene rubber and emulsion polymerized butadiene / acrylonitrile copolymer.

In one aspect of the invention, emulsion polymerization-derived styrene / butadiene rubber (E-SB) having a relatively common styrene content of about 10 to about 28% bound styrene.
R) is used, and in some cases, E-SBR having a moderate to relatively high bound styrene content, i.e., a bound styrene content of about 30 to about 45% is used.

[0011] In the case of E-SBR, a relatively high styrene content of about 30 to about 45% is believed to be advantageous in increasing the traction or skid resistance of the tire tread. The presence of E-SBR itself is particularly true for solution-polymerized SBR
Compared to the case where (S-SBR) is used, it is considered to be advantageous for enhancing the processability of the uncured elastomer composition mixture.

[0012] E-SBR by emulsion polymerization means that styrene and 1,3-butadiene are copolymerized as an aqueous emulsion. Such is well known to those skilled in such a field. The bound styrene content can vary, for example, from about 5 to about 50%.

In one aspect, the E-SBR also includes acrylonitrile in an amount such as from about 2 to about 30% by weight of bound acrylonitrile in the terpolymer to form an E-SB.
A terpolymer rubber can be formed as AR.

Emulsion polymerized styrene / butadiene / acrylonitrile copolymer rubbers containing from about 2 to about 40% by weight of bound acrylonitrile in the copolymer are also contemplated as diene-based rubbers for use in the present invention.

The bound styrene content of the solution polymerization prepared SBR (S-SBR) is generally from about 5 to about 50%, preferably from about 9 to about 36%. S-SBR can be conveniently produced, for example, by organolithium catalysis in the presence of an organic hydrocarbon solvent.

The purpose of using S-SBR is that when it is used in a tire tread composition, the hysteresis is lower, and as a result, the rolling resistance of the tire is improved. 3,4-polyisoprene rubber (3,4-PI)
When used in tire tread compositions, it is believed to be advantageous in increasing the traction of the tire. 3,4-
For PI and its use see US Pat. No. 5,087,
No. 668, which is incorporated herein by reference. Tg is the glass transition temperature and can be conveniently measured with a differential scanning calorimeter at a heating rate of 10 ° C./min.

The cis-1,4-polybutadiene rubber (B
R) is considered to be advantageous for increasing the wear resistance of the tire tread, that is, the tread wear resistance. Such BR can be produced, for example, by organic solution polymerization of 1,3-butadiene. The BR is conveniently characterized, for example, by having a cis-1,4-content of at least 90%.

The cis-1,4-polyisoprene and cis-1,4-polyisoprene natural rubber are well known to those having skill in the rubber art. As used herein and conventionally, "phr" refers to "rubber or elastomer 1".
Parts by weight of each material per 100 parts by weight ".

The pneumatic tire of the present invention comprises: (a) a carcass reinforced with a biased or radially extending cord, two axially spaced bead portions, and two axially spaced bead portions. Spaced apart sidewall portions, a portion adjacent each bead portion and a crown portion intermediate the sidewall portions, (b) a belt structure extending radially outwardly of the carcass at the crown portion, and (c). It is of a general design with a radially outer tread portion of the belt structure. The rubber component of the tire of the present invention containing the liquid organic polysulfide polymer may be in the carcass, belt structure and / or tread. For example, as a carcass part, the members are Apex, wire coat, ply coat, squeegee compound,
Gum strip, chafer, reinforced side wall insert,
Alternatively, it may be an exposed side wall. As part of the tread portion, the member may be a tread base or a tread cap. The compound may also be an inner liner.

The rubber composition used for the rubber member of the tire of the present invention contains a curable liquid polysulfide polymer. The molecular weight of these polysulfide polymers is 500
〜１０10,000. Preferably, the molecular weight of the polysulfide polymer is between 1,000 and 8,000. Preferred liquid polysulfide polymers have the general formula

[0021]

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(Where x is 4 to 59). Preferred polysulfides are those wherein x is 5
50. Commercially available liquid polysulfide polymers of Formula I that can be used in the present invention include LP
-2, LP-3, LP-12, LP-31, LP-3
2, LP-33, LP-977 and LP-980. These polysulfide materials are manufactured by Tray Thiokol and Morton International.

A variety of commercially available liquid polysulfide polymers include their mercaptan content (%),
Average molecular weight, pour point and average viscosity at 4 ° C (Poise)
It is characterized by LP-3 has a mercaptan content of 5.9 to 7.7%, an average molecular weight of 1000, and 4 ° C.
Is 90 poise. LP-33 has a mercaptan content of 5.0 to 6.5% and an average molecular weight of 100.
0, pour point is -23 ° C, average viscosity at 4 ° C is 165 poise. LP-977 and LP-980 each have a mercaptan content of 2.5-3.5% and an average molecular weight of 25.
The pour point is 4 ° C. and the average viscosity at 4 ° C. is 770 poise. The mercaptan content of LP-2 is 1.7-2.
2%, average molecular weight 4000, pour point 7 ° C, average viscosity at 4 ° C 3800 poise. LP-32 has a mercaptan content of 1.5 to 2%, an average molecular weight of 4000,
The pour point is 7 ° C. and the average viscosity at 4 ° C. is 3800 poise. The mercaptan content of LP-12 is 1.5 to 2.0.
%, Average molecular weight 4000, pour point 7 ° C, average viscosity at 4 ° C 3800 poise. LP-31 has a mercaptan content of 1.0 to 1.5% and an average molecular weight of 800.
0, pour point is 10 ° C, average viscosity at 4 ° C is 7400 poise.

In addition to the above liquid polysulfides of the formula I, epoxy-terminated polysulfides may be used. For the purposes of the present invention, an epoxy-terminated polysulfide is a polysulfide having an epoxy group attached to the polymer chain at each of two or more residual sulfhydryl sites. One or a mixture of the above liquid polysulfides in stoichiometric amounts of epichlorohydrin, dichlorohydrin, 1,2-dichloro-3-hydroxypropane, diglycidyl ether of glycerol or di-epoxylated novoloc resin Epoxidation may be used to obtain an epoxy terminated liquid polysulfide. Epoxidation of liquid polysulfides in excess epichlorohydrin is disclosed in US Pat.
No. 3,549, which is incorporated herein by reference. LP-3 and LP-
Morton International's ELP-3 and ELP-, epoxy-terminated derivatives of 33 polysulfide
Consider that 33 has the formula:

[0025]

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(Where x is 4-59). The basic structure of another epoxy-terminated polysulfide, ELP-612, available from Morton International, Inc.

[0027]

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Wherein R ⁹ is a polysulfide compound and R ¹⁰ is an epoxy moiety. ELP-3 has an epoxy equivalent of 600 to 800 and an average molecular weight of 1250.
And the epoxy equivalent of ELP-612 is 300 to 33.
There are 0.

The liquid polysulfide polymer used in the present invention can be added to the rubber by common techniques such as in a mill or Banbury. The amount of liquid polysulfide polymer will vary greatly depending on the type of rubber and other compounds present in the vulcanizable composition. Generally, the amount of polysulfide polymer compound used is about 1 to about 20 phr, preferably 3 to about 10 phr.

The rubber composition may contain fillers (eg, silica, aluminosilicate, zeolite and / or carbon black) to contribute to the desired properties of the rubber member. Such fillers are 10-
A typical amount of 250 phr can be used. For example, when used, the silica filler may be added in an amount of 10 to 250 phr. Preferably, the silica is present in an amount of 15 to 100 phr.

Silicic pigments generally used for compounding rubber can be used as silica in the present invention.
Examples of such pigments are pyrogenic and precipitated siliceous pigments (silica) and aluminosilicates, with precipitated silica being preferred. Preferred siliceous pigments for use in the present invention are those obtained by acidification of a precipitated silica, such as a soluble silicate such as sodium silicate.

[0032] Such silicas might be characterized, for example, BET surface area measured using nitrogen gas, preferably about 40 to about 600 meters ² / g, more preferably from about 50 to about 300 meters ² /
g. The BET method for measuring surface area is Journalof the Ameri.
can Chemical Society, No. 60
Vol., P. 304 (1938).

[0033] Silica also includes dibutyl phthalate (DB).
P) an absorption value of about 100 to about 400, more usually about 150
~ 300. In addition, silica and the above alumina and aluminosilicate are expected to have a CTAB surface area of about 100 to about 220. CTAB surface area is the external surface area assessed by cetyltrimethylammonium bromide at pH 9. ASTM for setting up and evaluating this method
D 3849. CTAB surface area is a well-known method of characterizing silica.

Mercury surface area / porosity is the specific surface area measured by mercury porosimetry. In such a technique, after a heat treatment to remove volatiles, the mercury penetrates into the pores of the sample. The setting conditions are that 100 mg of sample are used; volatiles are removed for 2 hours at 105 ° C. and ambient atmospheric pressure; the measuring range is suitably from ambient to 2000 bar. Such evaluation is Wins
low, Shapiro, ASTM bulleti
n, p. 39 (1959) or according to DIN 66133. For such an evaluation, a CARLO-ERBA porosity meter 2000 may be used.

The average mercury porosity specific surface area of silica is about 10
It should be in 0~300m ² / g. A suitable pore size distribution for silica, alumina and aluminosilicate by such mercury porosity assessment is that less than 5% of the pores are less than about 10 nm in diameter; 60-90% of the pores have a diameter of about 10 nm.
~ 100 nm; 10-30% of the pores have a diameter of about 100
約 about 1000 nm; 5-20% of the pores have a diameter of about 100
It is considered here that it is larger than 0 nm.

Silica is expected to have an average ultimate particle size, measured by electron microscopy, of, for example, 0.01 to 0.05 microns, although silica particles may be smaller or, perhaps, larger. Is also good.

It is contemplated that various commercially available silicas may be used in the present invention. These are given by way of example only, but not by way of illustration: silica commercially available from PPG Industries under the designations Hi-SiL® 210, 243, etc .; designations such as Z1165MP and Z165GR from Rhodia. Silica, available under the trade name VN2, VN
3, silica available from BV3380GR and the like, and silica available from Huber, for example, under Huber Sil 8745.

As will be apparent to those skilled in the art, it is desirable to add a sulfur-containing organosilicon compound to the silica-containing rubber compound. Examples of suitable sulfur containing organosilicon compound is of the _{formula: Z-Alk-S n -Alk} -Z (II) ( wherein, Z is

[0039]

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Selected from the group consisting of R ¹ is an alkyl group having ¹ to 4 carbon atoms, cyclohexyl or phenyl; R ² is alkoxy having 1 to 8 carbon atoms, or Alk is a divalent hydrocarbon having 1 to 18 carbon atoms, and n is an integer from 2 to 8).

Specific examples of sulfur-containing organosilicon compounds of the formula II which can be used according to the invention are: 3,3'-bis (triethoxysilylpropyl) disulfide, 3,3'-
Bis (triethoxysilylpropyl) tetrasulfide, 3,3'-bis (triethoxysilylpropyl) octasulfide, 3,3'-bis (trimethoxysilylpropyl) tetrasulfide, 2,2'-bis (triethoxysilyl) Ethyl) tetrasulfide, 3,3'-bis (trimethoxysilylpropyl) trisulfide,
3,3'-bis (triethoxysilylpropyl) trisulfide, 3,3'-bis (tributoxysilylpropyl) disulfide, 3,3'-bis (trimethoxysilylpropyl) hexasulfide, 3,3'-bis (Trimethoxysilylpropyl) octasulfide, 3,3 '
-Bis (trioctoxysilylpropyl) tetrasulfide, 3,3'-bis (trihexoxysilylpropyl) disulfide, 3,3'-bis (tri-2 "-ethylhexoxysilylpropyl) trisulfide, 3,
3'-bis (triisooctoxysilylpropyl) tetrasulfide, 3,3'-bis (tri-t-butoxysilylpropyl) disulfide, 2,2'-bis (methoxydiethoxysilylethyl) tetrasulfide, 2,
2'-bis (tripropoxysilylethyl) pentasulfide, 3,3'-bis (tricyclohexoxysilylpropyl) tetrasulfide, 3,3'-bis (tricyclopentoxysilylpropyl) trisulfide, 2,
2'-bis (tri-2 "-methylcyclohexoxysilylethyl) tetrasulfide, bis (trimethoxysilylmethyl) tetrasulfide, 3-methoxyethoxypropoxysilyl 3" -diethoxybutoxysilylpropyl tetrasulfide, 2,2 ' -Bis (dimethylmethoxysilylethyl) disulfide, 2,2'-bis (dimethyl-sec-butoxysilylethyl) trisulfide, 3,3'-bis (methylbutylethoxysilylpropyl) tetrasulfide, 3,3'-bis (Di-t-butylmethoxysilylpropyl) tetrasulfide, 2,
2'-bis (phenylmethylmethoxysilylethyl) trisulfide, 3,3'-bis (diphenylisopropoxysilylpropyl) tetrasulfide, 3,3'-bis (diphenylcyclohexoxysilylpropyl) disulfide, 3,3'- Bis (dimethylethylmercaptosilylpropyl) tetrasulfide, 2,2'-bis (methyldimethoxysilylethyl) trisulfide,
2,2'-bis (methylethoxypropoxysilylethyl) tetrasulfide, 3,3'-bis (diethylmethoxysilylpropyl) tetrasulfide, 3,3'-bis (ethyldi-sec-butoxysilylpropyl) disulfide, 3, 3'-bis (propyldiethoxysilylpropyl) disulfide, 3,3'-bis (butyldimethoxysilylpropyl) trisulfide, 3,3'-bis (phenyldimethoxysilylpropyl) tetrasulfide, 3-phenylethoxybutoxysilyl3 '-Trimethoxysilylpropyltetrasulfide, 4,4'
-Bis (trimethoxysilylbutyl) tetrasulfide, 6,6'-bis (triethoxysilylhexyl) tetrasulfide, 12,12'-bis (triisopropoxysilyldecyl) disulfide, 18,18'-bis (trimethoxy Silyl octadecyl) tetrasulfide, 18,18'-bis (tripropoxysilyloctadecenyl) tetrasulfide, 4,4'-bis (trimethoxysilyl-buten-2-yl) tetrasulfide,
4,4'-bis (trimethoxysilylcyclohexylene) tetrasulfide, 5,5'-bis (dimethoxymethylsilylpentyl) trisulfide, 3,3'-bis (trimethoxysilyl-2-methylpropyl) tetrasulfide, 3,3'-bis (dimethoxyphenylsilyl-2-methylpropyl) disulfide.

A preferred sulfur containing organosilicon compound of formula II is 3,3'-bis (trimethoxy or triethoxysilylpropyl) sulfide. The most preferred compounds are 3,3'-bis (triethoxysilylpropyl) tetrasulfide and 3,3'-bis (triethoxysilylpropyl) disulfide. Preferably, Z is

[0043]

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Wherein R ² is an alkoxy having 2 to 4, particularly preferably 2 carbon atoms;
Alk is a divalent hydrocarbon having 2 to 4, particularly preferably 3 carbon atoms; and n is an integer from 2 to 4.

The amount of the sulfur containing organosilicon compound of formula II in the rubber composition will vary depending on the amount of silica used. In general,
The amount of the compound of formula II can range from 0 to 1.0 per part by weight of silica.
Parts by weight. It is preferably from 0 to 0.4 parts by weight per part by weight of silica.

Carbon blacks commonly used in rubber compounding and commercially available can be used in the compositions of the present invention. Representative examples of such carbon blacks are those known by the following ASTM names: N1
10, N121, N134, N220, N231, N2
34, N242, N293, N299, S315, N3
26, N330, N332, N339, N343, N3
47, N351, N358, N375, N472, N5
39, N550, N582, N630, N642, N6
50, N660, N683, N754, N762, N7
65, N774, N787, N907, N908, N9
90 and N991. When using carbon black,
The amount can vary. Generally, the amount of carbon black will be from 0 to 250 phr. The amount of carbon black is 0
Preferably it is 150 phr. Silica coupling agents may be used with carbon black (ie,
Pre-mixed with the carbon black prior to addition to the rubber composition), such carbon black may be included in the above amounts of carbon black for compounding the rubber composition.

The rubber composition comprises various sulfur vulcanizable component rubbers and various commonly used additives such as curing aids such as sulfur donors, activators and retarders, oils and tackifying resins. Commonly known in the rubber compounding art, such as mixing processing aids such as resins and plasticizers, modified starches, pigments, fatty acids, zinc oxide, waxes, antioxidants and antiozonants, and peptizers. It will be readily appreciated by those skilled in the art that they will be formulated according to the methods used. As is known to those skilled in the art, the above additives are selected according to the purpose of using the sulfur-vulcanizable substance and the sulfur-vulcanized substance (rubber), and are usually used in general amounts. If a reinforced type of carbon black is used, its typical amounts for the present invention are as indicated herein. Representative examples of sulfur donors are elemental sulfur (free sulfur), amine disulfides, high molecular weight polysulfides and sulfur olefin adducts. The sulfur vulcanizing agent is preferably elemental sulfur. The sulfur vulcanizing agent may be used in an amount of 0.5 to 8 phr, preferably 0.5 to 6 phr. Typical amounts of tackifying or pre-reacted resin are from about 0.5 to about 10 phr, usually from about 1 to about 5 phr.
It is. Typical amounts of processing aids are from about 1 to about 50 phr. Examples of such processing aids are aromatic, naphthenic and / or paraffinic processing oils. Typical amounts of antioxidants are from about 1 to about 5 phr. Examples of representative antioxidants include monophenols, bisphenols and thiobisphenols, polyphenols, hydroquinone derivatives, phosphites, thioesters, naphthylamines, diphenylamine derivatives, para-phenylenediamines, quinolines, and others, such as Vanderbi
lt Rubber Handbook (1978),
p. 344-346. Typical amounts of antiozonants are about 1 to 5 phr. Representative examples of such antiozonants are para-phenylenediamines, such as diaryl-p-phenylenediamine, dialkyl-p-phenylenediamine and alkyl-aryl-p-phenylenediamine. If a fatty acid that can include stearic acid is used, its typical amount is from about 0.5 to about 3 phr. Typical amounts of zinc oxide are from about 2 to about 5 phr. Typical amounts of wax are from about 1 to about 5 phr. Often microcrystalline and paraffin waxes are used. Typical amounts of peptizers are from about 0.1 to about 1 phr. Common peptizers are, for example, pentachlorothiophenol and dibenzamidodiphenyl disulfide.

In one aspect of the invention, the sulfur vulcanizable rubber composition is then sulfur cured, ie, vulcanized. Accelerators are used to adjust the time and / or temperature required for vulcanization and to improve the properties of the vulcanizate. In one aspect,
A single accelerator system may be used, ie, a primary accelerator. First
The accelerator is present in an amount of about 0.5 to about 4 phr, preferably about 0.8 to about 4 phr.
It may be used in a total amount of about 3.0 phr. In another aspect, for activation and for improving the properties of the vulcanizate, the first
And a combination of secondary accelerators, the secondary accelerator being used in a lower amount, for example, from about 0.05 to about 3 phr. The combination of these accelerators is expected to produce a synergistic effect on the final properties, somewhat better than that produced by using any of the accelerators alone. In addition, delayed action accelerators may be used, which are not affected by normal processing temperatures, but perform satisfactory curing at normal vulcanization temperatures. Vulcanization retarders may also be used.
Suitable types of accelerators that can be used in the present invention are amines, disulfides, guanidines, thioureas, thiazoles, thiurams, sulfenamides, dithiocarbamates and xanthates. A peroxide curing agent may also be present. Preferably, the primary accelerator is a sulfenamide. If a second accelerator is used, the second accelerator is preferably a guanidine, dithiocarbamate or thiuram compound.

The rubber composition of the present invention may contain a methylene donor and a methylene acceptor. By “methylene donor” is meant a compound capable of reacting with a methylene acceptor (eg, resorcinol or its hydroxyl-containing equivalent) to yield a resin in situ. Examples of methylene donors suitable for use in the present invention include hexamethylenetetramine, hexaethoxymethylmelamine, hexamethoxymethylmelamine, lauryloxymethylpyridinium chloride, ethoxymethylpyridinium chloride, trioxane hexamethoxymethylmelamine (where the hydroxy group is an ester And partially esterified), and polymers of formaldehyde such as paraformaldehyde. Further, the methylene donor has the general formula:

[0050]

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Wherein X is alkyl having 1 to 8 carbon atoms, and R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are hydrogen, alkyl having 1 to 8 carbon atoms. , And the group-
Independently selected from the group consisting of CH ₂ OX)
It may be a substituted oxymethylmelamine. Examples of specific methylene donors are hexakis- (methoxymethyl) melamine, N, N ', N "-trimethyl / N, N', N" -trimethylolmelamine, hexamethylolmelamine,
N, N ', N "-dimethylolmelamine, N-methylolmelamine, N, N'-dimethylolmelamine,
N ', N "-tris (methoxymethyl) melamine and N, N', N" -tributyl-N, N ', N "-trimethylolmelamine N-methylol derivatives of melamine are prepared by known methods. Is done.

[0052] The amounts of methylene donor and methylene acceptor in the rubber compound can vary. Generally, the amount of methylene donor and methylene acceptor present is each about 0.1 to 1
0.0 phr. Preferably, the amount of methylene donor and methylene acceptor present is each about 2.0 to 5.0.
phr.

The weight ratio of methylene donor to methylene acceptor can vary. Generally, the weight ratio is from about 1:10 to about 1
0: 1, preferably about 1: 3 to about 3: 1. When the compound of the present invention is used as a wire coat or bead coat for use in a tire, an organic cobalt compound that acts as a wire adhesion promoter may be present. When used, any organic cobalt compound known in the art that promotes adhesion of rubber to metal may be used. For example, suitable organocobalt compounds that can be used include cobalt salts of fatty acids such as stearic acid, palmitic acid, oleic acid, linoleic acid, and the like; aliphatic or cycloaliphatic carboxylic acids having 6 to 30 carbon atoms. Cobalt salts; cobalt chloride; cobalt naphthalate; cobalt carboxylate; and organocobalt-boron complexes commercially available under the name Manobond C from Wailaf & Luther, Inc., Trenton, NJ. Manobond C has the structure:

[0054]

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Wherein R ⁸ is an alkyl group having 9 to 12 carbon atoms. The amount of organocobalt compound that can be used depends on the specific properties of the organocobalt compound selected, especially the amount of cobalt metal present in the compound. Since the amount of cobalt metal will vary considerably with the organocobalt compound suitable for use, the amount of organocobalt compound used is most suitably and conveniently based on the amount of cobalt metal desired in the finished formulation. Accordingly, the amount of organocobalt compound present in the compounding composition may range from about 0.01 to about 0.35% by weight, based on the total weight of the rubber compounding composition, of cobalt metal, preferably the total weight of the skim compounding composition. About 0.03 to about 0.2% by weight based on
It should generally be said that the amount should be sufficient to be cobalt metal.

The mixing of the rubber composition can be carried out by methods known to those skilled in the rubber mixing art.
For example, the components are generally mixed in at least two stages, at least one non-productive stage and a subsequent productive mixing stage. The final curing agent, including the sulfur vulcanizing agent, is typically mixed in a final stage, commonly referred to as a "productive" mixing stage, where the mixing temperature is lower than in the previous non-productive mixing stage. Ie, at the final temperature. The rubber, silica, compound of formula II and carbon black (if used) are mixed in one or more non-productive mixing stages. The terms "non-productive" and "productive" mixing stage are terms well known to those having skill in the rubber mixing art. The liquid polysulfide may be added at any mixing stage, but is preferably added at a non-productive stage. At least a portion of the rubber and generally silica, and, if used,
The rubber composition containing the sulfur-containing organosilicon compound of Formula II is mixed in a thermomechanical mixing step. The thermomechanical mixing process
Time suitable for bringing the rubber temperature to 140-190 ° C,
Generally involves machining in a mixer or extruder. Suitable times for thermomechanical processing vary as a function of operating conditions, volume and nature of the components. For example, the thermomechanical treatment can be for 1 to 20 minutes.

The above tread rubber composition is used for producing a tire assembly having a tread containing the above rubber composition. Thereafter, such a tire is vulcanized. Accordingly, the present invention relates to vulcanized tires manufactured using the liquid organic polysulfides described herein.

The vulcanization of the pneumatic tire of the present invention is about 100.
Perform at a general temperature of ~ 200 <0> C. Preferably, the vulcanization is performed at a temperature of about 110-180 ° C. Any conventional vulcanization method such as heating in a press or mold, heating with superheated steam or hot air or in a salt bath may be used.

The pneumatic tires of the present invention are tires for passenger cars, aircraft, agriculture, earth movers, off-roads, trucks, and the like. Preferably, the tire is a passenger or truck tire. The tire may be a radial tire or a bias tire, and a radial tire is preferable.

[0060]

EXAMPLES Example 1 Three samples were prepared to determine the effect of adding an organic polysulfide polymer to a model rubber composition. One of the polysulfides was LP-2 and the other was LP-31. LP-2 has the characteristics represented by Formula I and has an average molecular weight of 4000. LP-31 is represented by Formula I and has an average molecular weight of 8000. The components of each of the three rubber samples are shown in Table 1 below. Table 2 shows the physical properties of each of the three samples. Samples were prepared with the standard two non-productive, one productive mixing procedure.

[0061]

[Table 1]

1. 1. 40% styrene emulsion-polymerized styrene / butadiene copolymer elastomer containing 37.5 phr of extender oil, obtained as SBR1721 from Enikem; Buddha from Goodyear Tire and Rubber
2. cis-1,4-polybutadiene obtained as dene®; 3. Silica available as Z1165 from Rhodia; A composite material in the form of a 50/50 blend of bis (3-triethoxysilylpropyl) disulfide and carbon black. Thus, silane is considered to be 50% of the composite; 5. Obtained from Morton International; 6. Obtained from Morton International; N134; and 8. Sulfenamide and guanidine type accelerators

[0063]

[Table 2]

The advantages of the present invention can be seen in the data above. For example, Sample 1 (control) having a heat aging resistance value of 78.5 minutes and Samples 2 and 3 having a value exceeding 120 minutes.
It can be seen from the comparison with that that the heat aging resistance is more excellent. Same modulus value (100% and 300
%) Shows that the hardness value is higher. This property can be seen from the improvement in tread wear resistance when used as a tread compound. It can be seen that utilizing the present invention, the viscosity is lower (45.2 vs. 41 and 41.5). Lower viscosities have advantages in processing because they consume less energy.

Example 2 Five rubber samples were prepared to determine the effect of adding an organic liquid polysulfide polymer to a natural rubber / polybutadiene composition. Four liquid polysulfides were evaluated. 5
The components in each of the three samples are shown in Table 3 below. Table 4 shows the physical properties of each of the five samples.

[0066]

[Table 3]

1. 1. Nd-catalyzed high cis (98%) polybutadiene obtained from Bayer as Buna® CB24; N134; A composite material in the form of a 50/50 blend of bis (3-triethoxysilylpropyl) tetrasulfide and carbon black. Thus, the silane is considered to be 50% of the composite; and Sulfenamide and guanidine type accelerators

[0068]

[Table 4]

The data in Table 4 demonstrates some of the benefits of the present invention. It can be seen that the samples of the present invention (samples 2 to 5) have higher hot (100 ° C.) elastic rebound values than the control (sample 1). Due to the higher hot elastic repulsion values, lower rolling resistance (improved) and less heat generation are expected. The tan delta values at 100 <0> C for samples 2-5 are lower than the control. In addition, the G ″ values of samples 2-5 are lower and the G ′ values are higher than controls.

While certain representative embodiments and details have been set forth for the purpose of describing the invention, it will be appreciated by those skilled in the art that various changes can be made without departing from the spirit or scope of the invention. It is clear.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60C 15/06 B60C 15/06 BC 17/00 17/00 B // (C08L 21/00 (C08L 21 Applicant 590002976 1144 East Market Street, Akron, Ohio 44316-0001, U.S.A. S. A. (72) Inventor Tom Dominic Lanste Luxembourg, Grand Duchy of Luxembourg El-9370, Gilsdorf, Umm Aare Basel 6 (72) Inventor Marc Jules-Alexi Enoumon Bey-6720, Abbey-La-Nou, Belgium Vue, Rue de la Chapelle Numero 27

Claims (3)

[Claims] 1. A pneumatic tire including a rubber member, wherein the member has (a) 100 parts by weight of at least one elastomer containing olefinic unsaturation, (b) a molecular weight of 500 to 10,000, and a general formula: Embedded image A pneumatic tire, characterized by 1-20 phr of a liquid organic polysulfide polymer of the formula wherein x is 4-59 or epoxy terminated. 2. An elastomer containing an olefinic unsaturation is selected from natural rubber, neoprene (registered trademark), polyisoprene, butyl rubber, polybutadiene, styrene-butadiene copolymer, styrene / isoprene / butadiene rubber, methyl methacrylate-butadiene copolymer, isoprene- The pneumatic tire according to claim 1, wherein the pneumatic tire is selected from the group consisting of styrene copolymer, methyl methacrylate-isoprene copolymer, acrylonitrile-isoprene copolymer, acrylonitrile-butadiene copolymer, EPDM, and a mixture thereof. 3. The method according to claim 1, wherein the rubber member is an apex.
x), wire coat, ply coat, squeegee compound, gum strip, chafer
The pneumatic tire according to claim 1, wherein the pneumatic tire is selected from the group consisting of: r), an inner liner, a reinforced sidewall insert, a tread portion, and an exposed sidewall.